DE102014201167A1 - Thermal management system for an internal combustion engine - Google Patents

Abstract

A thermal management system for an internal combustion engine (12) has an engine cooling circuit (36), a main radiator circuit (46) with a main radiator (14), a heating circuit (50) with a heating heat exchanger (16), a coolant pump (18), the coolant through the circuits moves, and a rotary valve (20) having at least one switched and at least one unswitched input (42, 48, 52, 60), wherein the heating return (51) opens into a switchable input (52) of the rotary valve (20).

Description

The invention relates to a thermal management system for an internal combustion engine.

The thermal management of the coolant circuits of an internal combustion engine has a great influence on the fuel consumption. In particular, an operation of the engine at optimum temperatures and the efficient operation of consumers such as a vehicle interior heating, but also a rapid warming of the engine or transmission oil, help to save fuel.

In the DE 10 2005 035 121 A1 a cooling system is shown, which allows it to restrict the flow to the heater if necessary via a valve disposed in the heating circuit or completely inhibit. The disadvantage here, however, that with the valve an additional component must be installed.

The object of the invention is to provide a simple and cost-effective thermal management system, with which the individual coolant circuits of the internal combustion engine are flexibly controlled.

According to the invention this is achieved in a thermal management system for an internal combustion engine, comprising an engine cooling circuit, a main radiator circuit with a main radiator, a heating circuit with a heating heat exchanger, a coolant pump that moves coolant through the circuits, and a rotary valve with at least one switched and at least one unswitched input, wherein the heating return flows into a switched input of the rotary valve.

In general, the rotary valve has the advantage of temperature-independent switchability, which significantly increases the flexibility of the thermal management system compared to a conventionally used wax thermostat. Through the combination of switched and unswitched inputs, the rotary valve can be kept simple in construction and thus inexpensive and small in space.

The configuration according to the invention offers the possibility of shutting off or throttling the heating circuit independently of temperature, if no heating function is required. Due to the reduced heat emission as well as the reduced flow resistance for the coolant by eliminating the heating circuit in the flow path reduces the fuel consumption.

Since the heating circuit can be addressed separately, it is also possible to choose the flow conditions there so that an improved supply of heat is achieved for example by an increased volume flow through the heating heat exchanger with a total lower energy consumption.

In general, a rotary valve valve turns much faster than a thermostatic valve. This allows the internal combustion engine in the partial load range, in which the main radiator circuit is not open or only throttled open, warmer, that is with a higher coolant temperature than before, be responded to sudden load and thus temperature increases in the engine area by adjusting the rotary valve sufficiently fast can to keep the coolant temperature in the optimum range. For this purpose, for example, the heating circuit can be selectively shut off in the short term to increase a flow through the main cooler circuit.

On the other hand, the heating circuit can also be used to reduce a flow through the engine cooling circuit, for example, by a short circuit return from the engine cooling circuit to the rotary valve closed or throttled and so only the much lower flow rate is moved through the heating circuit. By throttling the flow through the engine cooling circuit, the internal combustion engine is cooled evenly and nevertheless, so that it reaches its optimum operating temperature faster during a cold start.

The engine cooling circuit forms here the so-called "small cooling circuit", in which essentially only the engine area, such as the cylinder head housing and the crankcase, is flowed through, but not the air-cooled main radiator of the vehicle.

It is also possible to throttle the flow of the engine cooling circuit or the crankcase to increase the heating effect.

The outlet of the rotary valve preferably leads directly into the engine cooling circuit inlet and is not switched.

The coolant pump is arranged, for example, downstream of the outlet of the rotary valve and upstream of the entry of the engine cooling circuit into the engine area in or in the immediate vicinity of an engine block of the internal combustion engine.

The return of the main cooler circuit and / or a return of the engine cooling circuit preferably open into a respective switched input of the rotary valve. By the switchable return of the engine cooling circuit in the rotary valve, a bypass (eg formed by the small cooling circuit) can be realized in a simple manner.

The rotary valve is advantageously arranged close to the engine to keep the flow paths, for example in the small cooling circuit short. For shorter engines, such as a four-cylinder in-line engine, it is possible to place the rotary valve on the front side of the engine block, preferably in close proximity to the optionally integrated in the engine block coolant pump. For longer engines, such as a six-cylinder in-line engine, it is often advantageous for reasons of space, to arrange the rotary valve on the longitudinal side of the engine block.

Normally, a transmission oil cooling circuit is provided with a transmission oil heat exchanger. Its return preferably opens into an unswitched input of the rotary valve. The transmission oil cooling circuit has a relatively slow temperature control, so that it is possible to provide in the transmission oil cooling circuit a separate thermostatic valve, which is designed in particular as a conventional wax thermostat. In this way, the transmission oil cooling circuit can be applied in parallel to the remaining cooling circuits and be coupled via the rotary valve to the remaining cooling circuits, in particular the engine cooling circuit. The transmission oil cooling circuit is switched autonomously via its own thermostatic valve. In this way, a control position of the rotary valve can be saved.

The transmission oil cooling circuit is preferably decoupled from the other cooling circuits and can be interrupted in the warm-up phase by the oil-side control to prevent heating of the coolant in the transmission oil cooling circuit and thus to support the heating of the internal combustion engine.

Preferably, a Motorabsperrventil is provided, the z. B. can interrupt a coolant supply line to the internal combustion engine downstream of the coolant pump.

In a warm-up phase, it is possible to close all switchable inputs of the rotary valve and thus largely restrict a flow through the engine cooling circuit.

Preferably, the motor shut-off valve is also closed, since this helps to avoid cavitation on the suction side of the coolant pump.

In the cooling circuits, a coolant surge tank is normally provided, which can accommodate a certain volume of coolant and can flow through the air to the outside.

The surge tank is preferably connected to an unswitched input of the rotary valve.

According to another possible embodiment, the surge tank is connected to a switched input of the rotary valve. This allows, for example, in a cold start of the internal combustion engine to prevent coolant circulation through the expansion tank, so that the stored there coolant volume is not heated and this amount of heat for faster heating of the internal combustion engine is available. The coolant pump is preferably driven mechanically, wherein the drive is coupled to the internal combustion engine. But it would also be possible to use an electrically driven main coolant pump.

When using a mechanically driven coolant pump, it is advantageous to provide an additional, electric coolant pump, which also at standstill of the internal combustion engine z. B. allowed after the end of a coolant movement through the coolant circuits.

It is possible to arrange the additional coolant pump in an exhaust gas turbocharger cooling circuit. This can be connected via an unswitched input of the rotary valve with the remaining cooling circuits. In another embodiment, the exhaust gas turbocharger cooling circuit opens into the main return of the engine cooling circuit.

The exhaust gas turbocharger cooling circuit is preferably not controlled by the rotary valve when it must supply in the wake situations after operation of the internal combustion engine via its additional coolant pump, the coolant movement in all still to be flown through cooling circuits and thus can always be open.

But the additional coolant pump can also be selectively controlled to direct coolant through certain positions of the rotary valve in certain cooling circuits. So it is possible, for example, to switch the rotary valve so that hot coolant is passed through the additional coolant pump in the heating circuit in order to increase the heating power, for example, at an im Framework of an automatic start stop (MSA) or other reasons switched off internal combustion engine.

Preferably, a control unit and temperature sensors are provided in the individual coolant circuits, and the rotary valve is switchable via the control unit in dependence on the data determined by the temperature sensors.

The thermal management system preferably has a map control in which specific data for the respective positions of the rotary valve in specific operating ranges are stored in the control unit. It is also possible to include other vehicle data in the control of the rotary valve, such as a selected driving style, the current or desired fuel consumption, a predictable position via GPS, the outside temperature or the currently engaged gear.

The invention will be described below with reference to two embodiments with reference to the accompanying drawings. In the drawings show:

1 a schematic view of a thermal management system according to the invention according to a first embodiment; and

2 a schematic view of a thermal management system according to the invention according to a second embodiment.

1 shows a thermal management system 10 for an internal combustion engine 12 (here a series four-cylinder gasoline engine).

Coolant flows through, inter alia, an engine block of the internal combustion engine in several coolant circuits 12 , an air-cooled main cooler 14 and a heater core 16 , The coolant is mainly due to a mechanically driven coolant pump 18 emotional.

The coolant flows are via a rotary valve 20 controlled, whose inputs are connected to the return lines of the coolant circuits and whose output in direct flow communication with the coolant pump 18 stands, as described in detail later.

In addition, there is still a coolant expansion tank 22 , a transmission oil heat exchanger 24 , an engine oil heat exchanger 26 and an additional, electrically operated coolant pump 28 provided, the latter with a heat exchanger (housing cooling) of an exhaust gas turbocharger 30 is in fluid communication. The electrically driven additional coolant pump 28 has in this example a power of about 20-150 W.

The main cooler 14 is through a fan 32 supported. There is also an additional cooler 34 intended to support the main radiator, which may be formed, for example, as Radhauskühler.

In an engine cooling circuit 36 (also referred to as "small cooling circuit") is cold coolant from the coolant pump 18 to an engine block of the internal combustion engine 12 , more precisely to cooling ducts in the cylinder head housing and in the crankcase, transported, where it absorbs waste heat, before it in a line 38 is collected. From the manifold 38 leads a short circuit line 40 to a first switched input 42 of the rotary valve 20 , The short circuit line 40 also forms the return of the engine cooling circuit 36 ,

The engine cooling circuit 36 is here by a motor shut-off valve 43 in its coolant supply line downstream of the coolant pump 18 interruptible.

From the manifold 38 goes a coolant line 44 that part of a main cooler cycle 46 is that through the main cooler 14 and about a return 47 to a switched second input 48 of the rotary valve 20 leads back.

From the line 44 branches an inlet of a heating circuit 50 in which the heating heat exchanger 16 is arranged, which can deliver heat to a vehicle interior. The return 51 of the heating circuit 50 leads to a third switched input 52 of the rotary valve 20 ,

A non-switched, single output 53 of the rotary valve 20 leads over a short line 55 to the coolant pump 18 ,

The position of the or the rotary valve of the rotary valve 20 and thus the degree of opening of the switched inputs 42 . 48 . 52 is from a control unit 54 predetermined, which can form part of an engine electronics. In the control unit 54 are stored data that a map control in dependence on predetermined operating conditions of the internal combustion engine 12 enable. In this example, the states of other components such as the heating heat exchanger 16 , the exhaust turbocharger 30 , the engine oil heat exchanger 26 as well as data from temperature sensors 56 in the engine block or in the coolant line 44 to the main cooler 14 considered. In dependence of These parameters are the position of the switched inputs of the rotary valve 20 established.

The additional electric coolant pump 28 is located in an exhaust gas turbocharger cooling circuit 58 that the exhaust turbocharger 30 cools and the in a non-switched input 60 of the rotary valve 20 empties. The exhaust gas turbocharger cooling circuit is supplied 58 through a branch from the engine cooling circuit 36 (not shown here).

The engine oil heat exchanger 26 is directly with the manifold 38 the engine cooling circuit 36 connected. Cold coolant is through a branch 62 after the coolant pump 18 fed. A control is not provided in this example, but would be realized by an additional thermostat.

The coolant expansion tank 22 leads over a connecting line 70 to the return of the exhaust gas turbocharger cooling circuit 58 which is in the non-switched entrance 60 of the rotary valve 20 empties. vent lines 72 and 74 connect the coolant expansion tank 22 with the engine cooling circuit 36 , more precisely, the manifold 38 and the inlet to the main cooler 14 in the main cooler circuit 46 , The transmission oil heat exchanger 24 is located in one of the rotary valve 20 independent transmission oil cooling circuit 76 and is powered by its own thermostatic valve 78 connected. This is a conventional wax thermostat which at a predetermined temperature the transmission oil cooling circuit 76 opens and closes below this temperature.

The transmission oil cooling circuit 76 leads through the engine block in a supply line 80 in the coolant line 55 empties. The mouth point is upstream of the coolant pump 18 but downstream of the exit 53 of the rotary valve 20 , From the engine cooling circuit 36 branches between the coolant pump 18 and the engine shut-off valve 43 a line 82 off, through the main radiator 14 and back to the transmission oil heat exchanger 24 leads (low-temperature loop). This is only necessary for vehicles with transmission cooling.

The coolant pump 18 is right here in the engine block of the internal combustion engine 12 integrated. The rotary valve 20 is in this embodiment, the front side of the engine block of the internal combustion engine 12 in the immediate vicinity of the coolant pump 18 stated.

Will the entrance 48 of the rotary valve 20 through the control unit 54 closed, so the coolant flow through the main radiator 14 in the main cooler circuit 46 prevented. This condition is especially when starting the internal combustion engine 12 as well as in a partial load operation.

Is the entrance 42 of the rotary valve 20 open, so the coolant flows through the short-circuit line 40 from the hot side of the internal combustion engine 12 directly into the rotary valve 20 and is from there via the coolant pump 18 directly on the cold side of the internal combustion engine 12 recycled.

If the entrance 52 of the rotary valve 20 In addition, coolant flows through the heating circuit 50 over the heating heat exchanger 16 ,

The circuit of the inputs 42 and 52 allows several operating states. If both the entrance 42 as well as the entrance 52 are open, the engine cooling circuit 36 and the heating circuit 50 flows through in parallel. The flow conditions are chosen so that a significantly larger volume flow through the engine cooling circuit 36 flows as through the heating circuit 50 as is known. In this operating state, for example, the internal combustion engine 12 to heat to their operating temperature while the vehicle interior is heated.

Is the entrance 42 completely or partially closed, reduces the flow through the engine cooling circuit 36 , so the load on the coolant pump 18 is reduced. Through the open heating circuit 50 Heat can be given off and a targeted circulation of the coolant can be maintained. Due to the higher flow resistance, the coolant volume flow through the internal combustion engine 12 reduced. This can be used for faster heating during a cold start.

Is the entrance 52 switched fully or partially closed, so is the heating circuit 50 uncoupled and is not flowed through. This is the one case, if no heating function is desired, so the vehicle occupants have turned off the heater.

Another purpose is a driving situation in which the load of the internal combustion engine 12 suddenly rises, for example, when driving uphill or abruptly accelerating. In this case, closing the heating circuit will result 50 in combination with the opening of the entrance 42 the engine cooling circuit 36 and optionally the entrance 48 of the main cooler cycle 46 to that the entire coolant flow for cooling the internal combustion engine 12 is available so that temperature peaks are avoided.

In the warm-up phase of the internal combustion engine, the inputs 42 . 48 and 52 be closed to a flow of coolant in the engine cooling circuit 36 (largely) to interrupt and thus achieve a faster warming. For cavitation on the suction side of the coolant pump 18 To prevent, here is also the engine shut-off valve 43 closed.

The connection and disconnection of the main cooler circuit 46 is done by opening or closing the input 48 of the rotary valve 20 , This can (within the given training of the rotary valve 20 ) regardless of opening or shutting off the engine cooling circuit 36 and the heating circuit 50 and also independent of temperature by specifications of the control unit 54 respectively.

The flow through the engine can here, among other things, during warm-up and in relevant consumption cycles for optimum heat distribution and friction optimization by controlling the rotary valve 20 and the engine shut-off valve 43 to be controlled. These functions are also in the control unit 54 stored.

The control unit 54 It also has a stored ventilation program, which provides a control sequence for different positions of the rotary valve 20 includes.

This program can be executed, for example, for maintenance purposes in a workshop equipped for this purpose. The internal combustion engine 12 while idling. If the normal idle speed is insufficient, the speed can be raised briefly or even during the Entlüftungsprograms the idle speed can be raised to a much higher level.

By targeted opening and closing of the individual coolant circuits, such as the engine cooling circuit 36 , the main cooler cycle 46 and the heating circuit 50 Can specifically in the lines existing air through the vent lines 72 . 74 to the expansion tank 22 be transported, where the air is separated.

This control of the switchable inputs 42 . 48 . 52 of the rotary valve 20 is completely independent of the control of the rotary valve 20 in other operating conditions and serves only the targeted guidance of the coolant through the vent lines 72 . 74 so that entrained air in the expansion tank 22 is deposited.

It may be useful, for example, to close all inputs at short notice and at predetermined intervals in order to introduce the coolant into the vent line 72 . 74 to press. It is also conceivable to specifically collect air in components and then by defined opening of the sub-circuits in the expansion tank 22 deposit.

Also, the individual coolant circuits can be briefly opened and closed again in quick succession, in order to transfer air from one circuit to the other and thus to the expansion tank 22 bring to.

In the same way, it is possible to selectively operate only one of the circuits at a time and possibly at the vent lines 72 . 74 open and close existing valves.

The venting program (s) are in the control unit 54 stored and can be retrieved in a maintenance mode or a mounting mode, in which case the control sequence is automatically executed.

2 shows a second embodiment of a thermal management system 10 ' , For already introduced components, the already known reference numerals continue to be used. Changed but similar components are designated by the known reference numeral with a dash.

Unlike the in 1 illustrated embodiment, the internal combustion engine 12 ' here a six-cylinder in-line engine, which leads to space reasons that the rotary valve 20 not the front side, but along a longitudinal side of the engine block of the internal combustion engine 12 is arranged.

Also for reasons of space leads the return 47 ' of the main cooler cycle 46 ' piece by piece through the engine block of the internal combustion engine 12 ' to the switched entrance 48 ' of the rotary valve 20 ,

In the physical arrangement in the rotary valve 20 corresponds to the entrance 42 ' in the second embodiment, the entrance 42 in the first embodiment and vice versa. The function of the rotary valve 20 however, it is analogous to that in the first embodiment.

In this embodiment, the return of the exhaust gas turbocharger cooling circuit opens 58 ' upstream of a branch of the short-circuit line 40 ' to the rotary valve 20 into the pipe 44 ,

The inlet of the exhaust gas turbocharger cooling circuit 58 ' branches off downstream of an outlet the engine block from a supply line 82 the transmission oil cooling circuit 76 ' to the main cooler 14 from. As in the first example, the return of the transmission oil cooling circuit 76 ' from the transmission oil heat exchanger 24 on the unswitched input 60 of the rotary valve 20 ,

The connection line 70 from the coolant expansion tank 22 opens here in the return of the transmission oil cooling circuit 76 ' which is not connected to the entrance 60 of the rotary valve 20 leads.

All related to 2 not described features are identical in structure and function to those in 1 described.

As the two embodiments described above, the inventive principle of using a rotary valve with switched and unswitched inputs for targeted separation of a heating circuit and the circuit of the engine circuit and the main cooler circuit, but also the central terminal of other cooling circuits such as the transmission oil cooling circuit and the exhaust gas turbocharger cooling circuit easily be implemented for various internal combustion engines in a flexible manner. Accordingly, the person skilled in the design of heat management systems according to the invention is free, wherein all the features of the two embodiments can be combined with one another at will or exchanged for one another.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102005035121 A1 [0003]

Claims (10)

Thermal management system for an internal combustion engine ( 12 . 12 ' ) with an engine cooling circuit ( 36 ; 36 ' ), a main cooler circuit ( 46 ; 46 ' ) with a main cooler ( 14 ), a heating cycle ( 50 ) with a heating heat exchanger ( 16 ), a coolant pump ( 18 ), which moves coolant through the circuits, and a rotary valve ( 20 ) with at least one switched input and at least one unswitched input ( 42 . 48 . 52 . 60 ), with the heating return ( 51 ) into a switchable input ( 52 ) of the rotary valve ( 20 ) opens. Thermal management system according to claim 1, characterized in that the return ( 47 ; 47 ' ) of the main cooler cycle ( 46 ) and / or a return ( 40 ) of the engine cooling circuit ( 36 ) into a switched input ( 48 . 42 ; 42 ' . 48 ' ) of the rotary valve ( 20 ) opens. Thermal management system according to one of the preceding claims, characterized in that a transmission oil cooling circuit ( 76 ; 76 ' ) with a transmission oil heat exchanger ( 24 ), whose return into an unswitched input ( 60 ) of the rotary valve ( 20 ) opens. Thermal management system according to one of the preceding claims, characterized in that in the transmission oil cooling circuit ( 76 ; 76 ' ) its own thermostatic valve ( 78 ) is provided. Thermal management system according to one of the preceding claims, characterized in that a surge tank ( 22 ) is provided for coolant which is connected to a non-switched input ( 52 ) of the rotary valve ( 20 ) connected is. Thermal management system according to one of the preceding claims, characterized in that an additional, electric coolant pump ( 28 ) is provided, in particular in an exhaust gas turbocharger cooling circuit ( 58 ; 58 ' ) is arranged. Thermal management system according to claim 6, characterized in that the rotary valve ( 20 ) can be switched so that via the additional coolant pump ( 28 ) warm coolant in the heating circuit ( 50 ). Thermal management system according to one of the preceding claims, characterized in that a control unit ( 54 ) as well as temperature sensors ( 56 ) are provided in the circuits and the rotary valve ( 20 ) via the control unit ( 54 ) depending on the temperature sensors ( 56 ) determined data is switchable. Thermal management system according to one of the preceding claims, characterized in that the rotary valve ( 20 ) can be switched so that a flow through the engine cooling circuit ( 36 ) is throttled. Thermal management system according to one of the preceding claims, characterized in that the rotary valve ( 20 ) can be switched so that in a warm-up phase of the internal combustion engine all switchable inputs of the rotary valve ( 20 ) are closed.

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